In my opinion Facebook is a great way to promote anything to everyone. Just keep in mind that Facebook can also work against you, fast.
I'm apart of the age group that started with Facebook (24 years old). Facebook started out as a "college only" audience. It WAS great. A way for me to connect with my friends I missed in high school. Now, I could care less about having a profile. I got rid of mine. Toooooooooooooooo much of a social drama (in my opinion).
It just depends on how you're using it. The only way I can see it hurting you is if you were using it as a medium of communication (blog "what you're doing that instant".) and as a promotional tool. The two can't mix on facebook. I would save the blogging for a personal account.
However, because over 500 million people use Facebook, with over 50% of them logging in daily (
http://www.facebook.com/press/info.php?statistics), you can benefit off that potential audience. If you're buy a college or university, I would promote student specials.
Another benefit to having a facebook account is the fact that you can just give people your account. This helps eliminate the
www.whattheheckwasthatinternetaddress.??? com, org, net, biz, and so on....